The present invention generally relates to a blood sampling unit and a method for sampling blood used for injection of medication or withdrawal of blood and fluid samples from a patient or donor. More specifically, the invention relates to protecting individuals from unintentional contact with an exposed needle point during assembly, use and disassembly of an evacuated tube blood sampling unit used for clinical procedures.
It is, of course, known to collect blood from an individual and test same. Such testing may be performed for diagnostic procedure or as part of blood collection.
For example, when a unit of blood is collected from an individual, one or more sample tubes of blood are collected. Samples for routine hematology analysis are collected from venous blood. Most commonly, the blood is pulled by a vacuum into sealed evacuated containers. The blood samples are then subjected to various tests, e.g., compatibility.
A conventional device used for blood sampling includes an adapter having, at a first end, a pointed cannula for accessing a tube, such as an evacuated tube. A threaded hub is located in the middle of the adapter allowing the adapter to be received by a holder for holding the evacuated tube. At a second end of the adapter, a second cannula for accessing a blood fluid flow path is provided.
To use the conventional blood sampling device, a tip protector covering the pointed cannula of the first end of the adapter is removed, exposing the pointed cannula. The adapter is then threaded into a tube holder.
Once the adapter is threaded onto the tube holder, the conventional clinical procedure of drawing blood can be performed. To this end, a second cannula, opposite the tube holder accesses the blood flow path. A vacuum tube is placed within the tube holder and receives the pointed cannula located within the tube holder. Blood will thereby flow from the blood flow path into the vacuum tube.
Because pointed cannulas are used, the adapter and method of collecting samples of blood provides the risk of accidental needlesticks. Although protective covers have been designed to reduce the risks of accidental needlesticks, in order to use the device, the covers must be removed.
A still further risk of needlesticks occurs when the adapter must be disposed of. After the clinical procedure is completed, the adapter and the contaminated needle must be disposed. Either the entire unit is disposed of, or the adapter and the needle are detached from the tube holder so that the tube holder can be reused. In any event, the sharp needle is once again exposed during disassembly.
Unfortunately, accidental needlesticks of healthcare personnel are common. Transmission of HIV by accidental needlesticks is estimated at about one out of every two hundred accidents. Risk of transmission increases by deep injections or injection of blood at the time of the needlestick. It is also known that hepatitis B is more frequently and easily transmitted than HIV by accidental needlesticks. While the risk of HIV transmission appears to be much lower than that of hepatitis B transmission, the potential consequences are much worse. See Merck Manual, 16th Edition, p. 79.
In addition to the use of covers, other attempts have been made to solve the problem of potential dangerous contact with both ends of the blood sampling unit. Recently, a blunt cannula, such as the Interlink.RTM. blunt cannula, has been used to prevent accidental needlesticks at a second end of the adapter, i.e., the end that accesses the blood fluid flow path. However, the first end of the adapter, because it is designed to pierce a rubber septum of an evacuated test tube, must be pointed. Thus, such adapter still provides the risk of accidental needlesticks.
A need, therefore, exists for an improved blood sampling device and a method for sampling blood to avoid potentially dangerous accidental needlesticks.